Spiral blower

ABSTRACT

A dryer blower for carwash facilities comprising a volute housing for an impeller having an axial intake and a tangential air outlet. The volute housing is characterized by a spiral channel of increasing cross-sectional area as a result of an increasing width and substantially constant radial dimension. The spiral housing terminates in a long, narrow output to create an air knife which effectively strips water from the surfaces of a just washed vehicle. The housing can be asymmetric or symmetric and housings can be arranged in side by side tandem to create additional length in the air outlet.

FIELD OF THE INVENTION

This invention relates to blowers for drying just-washed vehicles in an automatic or semi-automatic car wash.

BACKGROUND OF THE INVENTION

It is common in automatic and semi-automatic car washes to use electric motor-driven blowers to remove rinse water from just washed vehicles. In a typical drive through car wash, the blowers are mounted in multiples near the exit. They may also be mounted on rollover gantries.

Dryer blowers can take various forms; for example, rows of cylindrical tubes may be connected to an air plenum to direct air toward the surfaces of a vehicle. As another example, an air plenum or housing may be connected by rigid or flexible structures having long narrow outlets to create an air blade effect which drives rinse water from the surfaces of the vehicle, typically pushing the water from the front to back of the vehicle as it passes a dryer station.

Another example of dryer blower structures is the so-called “volute” or spiral blower wherein a motor driven impeller is mounted in a spiral housing with an axial air inlet. Air is collected around the impeller and spun toward a generally tangential outlet. The cross-sectional area of the air channel may be increased toward the outlet by gradually increasing the radial dimension of the housing such that it is a maximum next to the outlet.

Such a blower can be used essentially as is by mounting the blower housing such that the outlet is directed toward the exterior surface of a just-washed vehicle. The blower may also be converted to a blade-type dryer blower by adding a transition structure to the housing outlet. It is well known, however, that frictional drag in the transition section causes energy losses in the air stream and lowers the efficiency of the overall dryer system.

SUMMARY OF THE INVENTION

In the broadest sense, the present invention is an improved volute or spiral blower housing which accommodates a motor driven impeller to admit air axially to the impeller and in which the spiral air channel has a substantially constant radial dimension but increases in cross-sectional area as it progresses toward an outlet by virtue of increasing width such that the housing defines an air channel which progresses from a minimum width to a maximum width adjacent a tangential outlet. The outlet opening is preferably long and narrow so as to create an air knife or air blade effect without the need for an add-on transition section which produces energy losses.

In one form hereinafter described, the volute portion of the housing is asymmetric; i.e., one end wall is substantially planar while the other end wall moves progressively farther and farther away from the planar end wall to effect the increase in cross-section of the volute. In this embodiment, the motor itself is preferably mounted substantially within the volute such that the housing appears to “swallow” the motor while at the same time allowing substantial air circulation for cooling purposes. A screened inlet is created in or adjacent the essentially planar end wall and a transition section of conical shape may be employed to draw air into the impeller.

In another embodiment, two of the asymmetric housing blowers may be mounted side by side as to create a double-width, long, narrow air outlet, which can be used to remove water along the entire vertical or lateral dimension of a vehicle, even a large vehicle such as a van or truck. The air intakes are on the opposite outside ends of the tandem arrangement.

In a still third embodiment, a substantially symmetrical volute housing is created wherein both of the end walls progressively flare out and away from one another to create the air channel of increasing cross-sectional area.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an asymmetric housing blower in accordance with the invention;

FIG. 2 is a cross-sectional view of the blower of FIG. 1.

FIG. 3 is an exploded view of the embodiment of FIG. 3;

FIG. 4 is a perspective view of car wash dryer system using three sets of tandem mounted blowers of the type shown in FIGS. 1 and 2; and

FIG. 5 is a perspective view of a symmetrical housing blower in accordance with the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

Referring to FIGS. 1, 2, and 3 there is shown a dryer blower 10 for directing a high-velocity air stream at the exterior surfaces of a just-washed vehicle in a car wash facility. The blower 10 comprises an electric motor 12 having an output shaft 38 connected to spin an impeller 14 mounted within the confines of a volute housing 16, The housing may be rotoformed of a suitable material such as high-density polyethylene. The housing may be formed of other materials using other construction processes as will be apparent to those skilled in the art.

The housing 16 has on one side an essentially planar end wall 18 and on the other side an end wall 20 defining an air channel which increases in width, i.e., in the direction parallel to the axis of rotation of the motor 12 as it progresses toward an outlet section 22 having a long, narrow outlet opening 24. Air is inlet to the impeller through a cone 28 which is supported by a screw-mounted spacer 26 also supporting a safety screen 30. Annular plates 32 and 34 are provided for structural support to receive the screws 35. The impeller 14 is of conventional design with backward curved blades 36 and is mounted for rotation on the motor shaft 38 as previously described. The motor 12 has a typical switch box 44 and is mounted on a support bracket 42, partially enclosed within but spaced from the interior surface 45 of the housing 16.

In operation, the motor 12 is energized to rotate the impeller 14 drawing air through the screening 30 and the conical section 28 into the impeller 14. Air is collected by the impeller and rotated along the air channel defined by the housing 16 toward the transition section 22 and the long, narrow outlet 24. In this case, the length-to-width aspect ratio of the outlet 24 is approximately 12:1. It is to be understood that this aspect ratio is illustrative rather than limiting in nature.

FIG. 4 illustrates the manner in which blowers of the type illustrated in FIGS. 1 and 2 can be arranged in tandem to create even longer and higher aspect ratio outlets. In FIG. 4 a structural frame is constructed using aluminum or steel uprights 48 and 50 connected by an overhead horizontal beam 52. Clamping structures 54 and 56 are used to secure the horizontal beam 52 to the uprights 48 and 50 at a height which permits a vehicle to pass between the uprights 48 and 50 and under the horizontal beam 52.

The horizontal beam carries blowers 58 and 60 with the axial air intakes on the opposite outside surfaces; the intake safety screen 78 is shown on the far left side of the tandem combination 58, 60 as shown in FIG. 4. Therefore, the spiral end walls converge on one another as shown. Each blower 58, 60, has an impeller (not shown) driven by an electric motor 80 in exactly the same manner as was described with reference to the single blower arrangement of FIGS. 1 and 2. The two blowers 58 and 60 provide a long, narrow air outlet (not shown) which is aimed downwardly toward the top surfaces, windshield and rear window of a vehicle (not shown). A filler section 84 of plastic or other suitable material may be used to fill the conical gap between the two blowers 58 and 60 if desired.

Blowers 62 and 64 are mounted in tandem on the upright 48 with the air outlets 66 and 68 in side by side alignment to create a double length air blade, the dimensions of which can, by way of example, be up to about 90 inches.

On the other side, blowers 70 and 72 having outlet transition sections 74 and 76 respectively are mounted on the upright 50 to dry the opposite side of a vehicle passing between them. Transition sections such as that shown at 84 may be used in combination with all of the tandem mounted blowers 62, 64 and 70, 72 for aesthetic purposes as desired.

Referring now to FIG. 5, a blower 86 of alternative design is shown to comprise a symmetrical spiral housing 88 partially enclosing a motor 90 driving an impeller 92. Air is taken into the blower through a screened axial inlet 94. The housing 88 has opposite end walls 96 and 98 which spirally diverge from one another toward the outlet 100. Whereas one of the end walls in the embodiment of FIGS. 1 and 2 was essentially planar, both of the end walls 98 and 96 are non-planar and diverge evenly about a vertical center plane (not shown) which can be defined as passing through the center of the structure shown in FIG. 4.

Purely by way of illustration, the motors 12 and 90 may be of a ten horsepower rating and rotate at 3600 rpm to produce an air flow of between about 5,000 and 6,000 cubic feet of air per minute. Although the invention is not limited to these figures, they have been found to represent a commercially viable design suitable for use in many automatic and semi-automatic carwash installations. 

1. A blower for drying just washed vehicles comprising:: an annular impeller; a motor for driving the impeller; and a volute housing surrounding the impeller having an axis of rotation and an axial intake for air, an outlet, and a volute air channel leading to the outlet, characterized by a substantially constant radius and gradually increasing cross-sectional area.
 2. The blower as defined in claim 1 wherein the outlet is in the shape of a narrow rectangle having an aspect ratio of about 12:1.
 3. The blower defined in claim 1 wherein the volute is symmetric.
 4. The blower defined in claim 1 wherein the volute is asymmetric.
 5. The blower defined in claim 4 wherein one side of the volute is defined by a wall which is substantially planar and orthogonal to the axis of rotation while the opposite wall is non-planar to define said gradually increasing cross-sectional area.
 6. The blower defined in claim 1 wherein the housing is made of plastic.
 7. The blower defined in claim 6 wherein the plastic is high-density polyethylene.
 8. The blower as defined in claim 1 wherein the motor is at least partially enclosed by the volute housing.
 9. A tandem blower arrangement for drying just washed vehicles comprising: a pair of volute housing blower arranged in side-by-side relationship and including for each blower an impeller having an axis of rotation and an axial air inlet, the volute housing of each blower terminating in a long, narrow outlet, the blowers being arranged such that the long, narrow outlets are in alignment and are adjacent one another and the axes of rotation of the respective impellers essentially coincide.
 10. The tandem blower arrangement of claim 9 wherein the volute blower housings are asymmetric and are characterized by outside end walls that are essentially planar and inside end walls that diverge from the outside end walls and converge upon one another in a tandem arrangement.
 11. A housing for a volute air blower for car wash installations characterized by a spiral air channel which increases in cross-sectional area but remains substantially constant in radial dimension as it progresses toward a long narrow tangential outlet.
 12. A blower arrangement for directing air toward a wet vehicle comprising: a gantry; at least one blower arranged on the gantry immediately over a vehicle position to direct a substantially continuous long, narrow, volume of high velocity air at the vehicle to drive water along the length of the vehicle as the vehicle moves longitudinally relative to the gantry. 